All manner and variety of devices or appliances configured for the absorption of such body f1uids as menses are, of course, well known. Sanitary napkins are the most frequently used of these devices.
The effect of fluid run-off is apparent in all forms of sanitary napkins including those having increased absorbency and designed for heavy flow. It has been suggested that at least 20-25% of all sanitary napkins leak. To prevent this situation it is necessary to make many inconvenient pad changes at short intervals.
Thus, there have been several attempts in the art to minimize the undesirable side leakage problem associated with the use of sanitary napkins.
In U.S. Pat. No. 4,397,644 to Kimberly-Clark Corporation, there is described a sanitary napkin for feminine hygiene, which is capable of transmitting viscous menstrual fluid into the absorbent portion of the napkin to minimize cover run-off. The napkin has a fluid permeable cover which is integrated with a portion of the absorbent matrix. The sanitary napkin may be in the form of a thin sanitary napkin, mini-pad or liner, thereby extending its use as an undergarment protector to the time between menstrual periods.
The art has also offered several types of feminine protection devices which provide embossed lines for a variety of purposes. U.S. Pat. No. 3,395,201 describes a sanitary napkin wherein the longitudinal edge portions of the assemblage are bonded and the fiber density increased so that the longitudinal edge portions are stabilized. The edge portions provide strength and will not allow the short fibers to sift through the edges of the assemblage.
The technique of compressing the edges of a sanitary napkin was used in U.S. Pat. No. 3,559,650 to hold the pad and backing together while at the same time retarding the flow of fluid outwardly from the central longitudinal axis of the pad and retaining such fluid in the bulky portion of the pad.
U.S. Pat. No. 2,064,431 discloses a sanitary napkin wherein a pair of slits are provided at each end of the pad to allow the ends of the napkin to curve up when being worn.
Several patents have recognized the advantage of using embossed lines near the center of the pad. U.S. Pat. No. 3,411,504 describes a sanitary napkin which has in the top effective surface thereof, at least two longitudinal grooves or channels that lie in the mid-portion of the napkin and extend towards but terminate short of the extreme end portions of the napkin. U.S. Pat. No. 4,059,114 describes a disposable shield for garment protection having a very thin, lightweight, highly absorbent structure. The disposable shield contains one or more sets of embossed lines located near the center of the pad.
U.S. Pat. No. 3,575,174 discloses a sanitary napkin formed into a curved or tapered configuration which is structurally stabilized in that form by a pair of longitudinally extending channels embossed into the napkin from the top surface. Structural stability of the sanitary napkin in the transverse direction is also provided by forming deeply embossed channels adjacent to each end of the sanitary napkin, which channels interconnect the ends of the longitudinally embossed channels.
U.S. Pat. No. 2,787,271, however, describes a sanitary napkin having a pair of lateral flaps which are adapted to fold downwardly and bear against the opposed inner surfaces of the thighs of the wearer, for arresting any overflow once it has occurred.
The prior art has not attempted to develop an occlusive container out of the sanitary napkin to eliminate leakage. Embossed channels have been suggested yet they are not designed to allow the sides of the sanitary napkin to fold upwards during use.